Ch. 2

Question 1

Element

Answer 1

Simplest form of matter w/ unique chemical properties.

6 elements make up 98.5% of the bodys weight O, C, H, N, Ca, P

Question 2

Atom Structure

Answer 2

of electrons=# of protons

**Nucleus is at the center of each atom**
Inside the nucleus:
1. Protons- POSITIVELY charged
2. Neutrons- NEUTRAL
3. Electrons- NEGATIVELY charged
**Electrons orbit around the nucleus**

Atomic #- # of protons
Atomic mass- sum of protons+neutrons

Question 3

Isotopes

Answer 3

Variety of elements with same# of protons but DIFFERENT # of neutrons; UNSTABLE & decay giving off radiation called RADIOACTIVITY aka “radioisotopes”
[every element has at least 1 radioisotope]

Question 4

Ions

Answer 4

CHARGED particles; UNEQUAL # of protons & electrons

> Ionization- donating electrons to another atom
[++] CATION- Giving up electrons & becoming POSITIVELY CHARGED (1-3 valence electrons)
[- -] ANION- Gaining more electrons & becoming NEGATIVELY CHARGED (4-7 valence electrons)

Question 5

Electrolytes

Answer 5

Salts that ionize in water & form solutions capable of electricity [nerve & muscle function due to chemical reactivity, osmosis, electrical effects]

Question 6

Free Radicals

Answer 6

Odd # of electrons; UNSTABLE/short lived
Free radical damage-heart attack, cancer & other diseases

Antioxidants NEUTRALIZE free radicals (Vitamin C&E)

Question 7

Compounds

Answer 7

Made of 2 different elements (CO2)

Question 8

Isomers

Answer 8

SAME atoms but different chemical arrangement

Question 9

Chemical Bond

Answer 9

The force that holds atoms together

Question 10

Ionic Bond

Answer 10

Attraction between OPPOSITELY CHARGED ions (cation & anion); weak bonds

Question 11

Covalent Bond

Answer 11

Sharing of electrons
Single Covalent bond [H-H]- single pair of electrons
Double Covalent bond [H=H]- double pair of electrons

1. Non polar Covalent bond- electrons are shared equally
2. Polar covalent bond- electrons are shared unequally
3. Hydrogen bond- weak attraction between a hydrogen atom & another atom

Question 12

Properties of Water

Answer 12

• *UNIVERSAL solvent b/c more substances (solute) dissolve in it**
  1. Hydrophilic- dissolves in water (salt, sugar)
  2. Hydrophobic- does NOT dissolve in water (fats)

> Adhesion- cling to surfaces; good lubricant
Cohesion-attraction of molecules of the SAME substance [thermal stability, chemical reactivity]

Question 13

Acid vs Base

Answer 13

1. Acid- “proton donor”, releases a proton (H+) in water
2. Base- “proton acceptor”, releases hydroxides (OH-)

• *pH- measure concentration of H+ (0.0-14.0)
  0. 0 ACIDIC - 7 NEUTRAL - 14.0 BASIC

> Buffers are chemical solutions that resist changes in pH.

Question 14

Dehydration Synthesis vs. Hydrolysis

Answer 14

1. Dehydration Synthesis (take away water)-join monomers to form polymers
2. Hydrolysis (cutting it using water)- adds water to breakdown polymers

**Macromolecules are polymers (made up of monomers)

Question 15

Carbohydrates (SUGARS-STARCH-GLYCOGEN)

Answer 15

Broken down to glucose to provide energy [Hydrophillic]

1. Monosaccharides-simplest carb, glucose, fructose, galactose
2. Disaccharides- 2 monosaccharides, sucrose, lactose, maltose
3. Polysaccarides- glycogen, starch, cellulose, polymers of glucose

Question 16

Lipids

Answer 16

Made up of carbon, hydrogen, & oxygen. Fats.
>Triglycerides- solid at room temp, oil if liquid
-Built by dehydration synthesis [glycerol & fatty acid]
-Saturated fatty acid-contains as many hydrogen as it can
-Unsaturated fatty acid (good fats)-extra hydrogen can be added due to double carbon bonds

-Phospholipids- hydrophilic head & hydrophobic tail
[amphipathic-partly attracted to water & partly repelled]
-Steroids are synthesized from cholesterol

Question 17

Proteins

Answer 17

1. Structure (keratin in nails, collagen in bones/skin/teeth)
2. Communication (hormones/receptors)
3. Membrane transport (channels)
4. Catalysis
5. Movement & Cell adhesion

> Peptides- chain of amino acids linked by dehydration synthesis
Enzymes-proteins that enable chemical reactions to run faster
-Substrate is a substance the enzyme acts on
-Active site is a surface pocket on enzyme where it binds with substrate [TEMP and pH alter ability for binding]

Question 18

Nucleic Acids

Answer 18

1. DNA- contains genetic material & resides in nucleus

2. RNA- carries out orders given by DNA, smaller than DNA (uracil not thymine) (mainly in cytoplasm)

Question 19

Chemical Reactions [REACTANTS—>PRODUCTS]

Answer 19

Covalent or ionic bond is broken or formed

• Catabolism: energy releasing; break down
• Anabolism: adding to; energy storing
• Exergonic: energy releasing; produces energy
• Endergonic: requires & needs energy
• Oxidation: loss of electrons
• Reduction: gains electrons